The anticancer effects of ceramide have been reported in many types of cancers but less in lung cancer. In this study, we used C₂-ceramide to further investigate its possible anticancer effects and mechanisms on non-small cell lung cancer (NSCLC) H1299 cells. The result of cell proliferation in terms of trypan blue assay showed high dose of C₂-ceramide inhibited cell survival after 24 h treatment. The flow cytometry-based assays indicated the effect of apoptosis, chromatin condensation, and G₁ arrest in terms of Annexin V/propidium iodide (PI), DAPI, and PI stainings, respectively. Moreover, the decreased protein level of p-Akt, p-NFκB, survivin and cyclin A2 were detected by Western blot assay. Taken together, these results indicated the antiproliferative effect of C₂-ceramide is majorly responsible for cell apoptosis in lung cancer H1299 cells.

Patients with clear cell renal cell carcinoma (ccRCC) are often diagnosed with both von Hippel-Lindau (VHL) mutations and the constitutive activation of hypoxia-inducible factor-dependent signaling. In this study, we investigated the effects of long-term hypoxia in 786-O, a VHL-defective renal cell carcinoma cell line, to identify potential genes and microRNAs associated with tumor malignancy. The transcriptomic profiles of 786-O under normoxia, short-term hypoxia and long-term hypoxia were analyzed using next-generation sequencing. The results showed that long-term hypoxia promoted the ability of colony formation and transwell migration compared to normoxia. In addition, the differentially expressed genes induced by long-term hypoxia were involved in various biological processes including cell proliferation, the tumor necrosis factor signaling pathway, basal cell carcinoma and cancer pathways. The upregulated (L1CAM and FBN1) and downregulated (AUTS2, MAPT, AGT and USH1C) genes in 786-O under long-term hypoxia were also observed in clinical ccRCC samples along with malignant grade. The expressions of these genes were significantly correlated with survival outcomes in patients with renal cancer. We also found that long-term hypoxia in 786-O resulted in decreased expressions of hsa-mir-100 and hsa-mir-378 and this effect was also observed in samples of metastatic ccRCC compared to samples of non-metastatic ccRCC. These findings may provide a new direction for the study of potential molecular mechanisms associated with the progression of ccRCC.